Intravascular valve component with improved valve positioning

ABSTRACT

An intravascular valve component broadly includes a valve case and a flexible pressure-actuated flow control valve. The valve case includes attached proximal and distal case portions that present respective spaced apart fluid ports and a fluid passageway extending between the ports. The flexible pressure-actuated flow control valve is disposed within the fluid passageway and includes a slitted central valve wall and an annular flange surrounding the central valve wall. The annular flange includes a radially-extending flange wall and a projection extending axially from the flange wall, with the projection engaging one of the case portions to restrict radial movement of the flow control valve relative to the valve case.

BACKGROUND

1. Field

The present invention relates generally to infusion devices used for theadministration of various fluids to patients. More specifically,embodiments of the present invention concern an intravascular valvecomponent for a catheter.

2. Discussion of Prior Art

The use of intravenous devices for the administration of parenteral andother fluids to patients is a common practice. A variety of devices forsuch purposes have been proposed in the past, such as a simple length oftubing having a fitting on one end for making connection with a sourceof fluid (e.g., a bottle or flexible bag), while the other end isprovided with a needle or catheter which may be inserted into the veinof a patient. A persistent problem with prior infusion devices isreferred to as blood reflux, or the tendency for small amounts of bloodfrom the patient to be drawn into the infusion apparatus. Blood refluxcan occur in prior art devices, for example, when a gravity supply fluidsource is empty or when a cannula is removed from a septum or port.

Prior art pressure-activated infusion devices that reduce blood refluxusing a flexible check valve are problematic due tomanufacturing-related issues. Flexible check valves are notoriouslydifficult to align relative to the internal passage of the valvehousing. Off-axis misalignment of the check valve can cause the valve toinadvertently or prematurely open. Furthermore, prior art check valvesare also known to shift or “squirm” within the housing, often when thevalves are seated and secured in the housing. This inadvertent movementcan also cause valve misalignment and improper operation.

There is accordingly a need in the art for improved intravasculardevices equipped with a valve component that eliminates the possibilityof blood reflux and can be reliably manufactured.

SUMMARY

Embodiments of the present invention provide an intravascular valvecomponent that does not suffer from the problems and limitations of theprior art devices set forth above.

A first aspect of the present invention concerns an intravascular valvecomponent that broadly includes a valve case and a flexiblepressure-actuated flow control valve. The valve case includes attachedproximal and distal case portions. The case portions present respectivespaced apart fluid ports and a fluid passageway extending between theports. The flexible pressure-actuated flow control valve is disposedalong the fluid passageway to control fluid flow therethrough. The valveincludes a slit central valve wall and an annular flange surrounding thecentral valve wall. The annular flange includes a radially-extendingflange wall and a projection extending axially from the flange wall. Oneof the case portions presents an opening that receives the projectiontherein. The flange wall is engagingly received between the attachedcase portions, with the projection engaging the one of the case portionsto restrict radial movement of the flow control valve relative to thevalve case.

Other aspects and advantages of the present invention will be apparentfrom the following detailed description of the preferred embodiments andthe accompanying drawing figures.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

Preferred embodiments of the invention are described in detail belowwith reference to the attached drawing figures, wherein:

FIG. 1 is a perspective view of a catheter assembly constructed inaccordance with a preferred embodiment of the present invention, withthe catheter assembly including a peripheral catheter, an intravascularinjection site, and a blunt cannula;

FIG. 2 is an exploded proximal perspective view of the catheter assemblyshown in FIG. 1, particularly showing a luer lock fitting, a septumsupport body, a split septum unit, and a flow control valve of theinjection site;

FIG. 2 a is an enlarged perspective view of the luer lock fitting shownin FIGS. 1 and 2, showing the fitting cross-sectioned to depict agrooved valve seat, a male end extending distally from the valve seat,and a connector wall extending distally from the valve seat andsurrounding the male end;

FIG. 3 is an exploded distal perspective view of the catheter assemblyshown in FIGS. 1 and 2;

FIG. 3 a is a distal perspective of the flow control valve shown inFIGS. 2 and 3, showing the flow control valve cross-sectioned to depicta slit central valve wall and an annular flange surrounding the centralvalve wall, and further showing a radially-extending wall of the flangeand an endless annular projection extending distally from the flangewall;

FIG. 4 is a cross section of the catheter assembly shown in FIGS. 1, 2,and 3, showing the peripheral catheter connected to the luer lockfitting and the cannula removed from the split septum unit, and furthershowing the slit central valve wall in a closed configuration to preventinfusion and aspiration fluid flow;

FIG. 5 is a cross section of the catheter assembly shown in FIGS. 1, 2,3, and 4, showing the cannula inserted into the split septum unit andproviding infusion flow through the internal passageway presented by theinjection site, with the slit central valve wall in an open infusionconfiguration where internal opposed edges of the valve wall are shifteddistally and away from each other to allow infusion fluid flow throughthe valve;

FIG. 6 is a cross section of the catheter assembly shown in FIGS. 1, 2,3, 4, and 5, showing the cannula inserted into the split septum unit andreceiving aspiration flow from the internal passageway, with the slitcentral valve wall in an open aspiration configuration where theinternal opposed edges are shifted proximally and away from each otherto allow aspiration fluid flow through the valve; and

FIG. 7 is an enlarged cross section of the intravascular injection siteshown in FIGS. 1, 2, 3, 4, 5, and 6, showing the slit central valve wallin the closed configuration.

The drawing figures do not limit the present invention to the specificembodiments disclosed and described herein. The drawings are notnecessarily to scale, emphasis instead being placed upon clearlyillustrating the principles of the preferred embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Turning to FIGS. 1, 2, and 3, a catheter assembly 10 selected forillustration generally includes an injection site 12, a peripheralcatheter 14 secured to the distal end of the site 12, and a cannula 16removably inserted into the proximal end of the injection site. Theinjection site 12 is constructed in accordance with a preferredembodiment of the present invention. Although the injection site 12 isshown with the peripheral catheter 14 and cannula 16, it will beappreciated that the site 12 can be used in other applications. Forexample, the injection site 12 could be used with a central venouscatheter (CVC), another intravascular catheter, or a needle.Furthermore, the injection site 12 could be used with other types ofconnection components, tubing, etc. Moreover, as will be appreciated,the principles of the present invention are not limited to an injectionsite, but rather encompass any intravascular component utilizing theinventive valve arrangement described herein. Yet further, theillustrated catheter assembly 10 is similar in many respects to theassembly disclosed in co-pending U.S. application Ser. No. 11/277,471,filed Mar. 24, 2006, entitled INTRAVENOUS INJECTION SITE WITH SPLITSEPTUM AND PRESSURE ACTIVATED FLOW CONTROL VALVE, which is herebyincorporated in its entirety by reference herein.

The illustrated injection site 12 preferably includes a support body 18,a proximal split septum unit 20, a distal luer lock fitting 22, and aunitary pressure-actuated flow control valve 24. Again, it will be shownthat the injection site 12 could be alternatively configured withrespect to the critical aspects of the present invention. As usedherein, the terms “distal” and “proximal” refer, respectively, todirections toward and away from a patient.

In more detail, the illustrated peripheral catheter 14 is itselfentirely conventional and includes an annular proximal base 26 withdiametrically opposed connection tabs 28 for threaded connection to thefitting 22. The catheter 14 also includes a distally extending barrel 30and cannula 32 secured to the distal end of the barrel 30. As iscustomary, the cannula 32 is inserted into a patient so that medicamentscan be injected and fluids can be aspirated via the injection site 12.As previously mentioned, the principles of the present invention areequally applicable to other catheter designs, as well as othercomponents permanently or removably secured to the injection site 12.

The illustrated cannula 16 is also conventional in construction andpreferably includes a proximal annular base 34 and an externally ribbedbarrel 36 terminating in an elongated injection lumen 38. The base 34 ispreferably provided with diametrically opposed connection tabs 40configured for threaded connection with a standard luer lock fitting. Itis particularly noted that the cannula 16 is a so-called “bluntcannula,” preferably formed of a relatively rigid plastic and intendedto provide needleless connection with a septum. Although a needle couldconceivably be used with the injection site 12, those ordinarily skilledin the art will appreciate that a split septum is typically designed foruse with a blunt cannula. The illustrated cannula 16 is configured to beattached to other components for transferring fluid via the injectionsite 12 (in either of infusion and aspiration directions), such astubing, a syringe, or a gravity supply fluid source.

Turning to FIGS. 4-7, the support body 18 serves to support andinterconnect the septum unit 20 and luer lock fitting 22. The supportbody 18 preferably comprises a molded synthetic resin rigid body andincludes a septum well 42, a tubular mid-section 44, and a cup-likestructure that includes a valve seat 46 and a sidewall 48. The septumwell 42 presents a socket for receiving the septum unit 20, and thesocket is partly defined by a distal septum-engaging surface 50 and anannular interior groove 52 adjacent a proximal end of the septum well42. As will be discussed, the surface 50 is designed to restrict distaldisplacement of the septum when the cannula 16 is inserted therein and,more preferably, pre-compress the septum prior to cannula insertion. Thesurface 50 projects proximally to provide the desired degree ofpre-compression. Specifically, the surface 50 is rounded with a centralapex 53, and the surface 50 preferably extends in a proximal directionat least about 0.015 of an inch (measured axially from the distalmostcircumferential periphery of surface 50 to the central apex 53). Morepreferably, the “height” of the surface is about 0.026 of an inch.However, the principles of the present invention are equally applicablewhere the septum well 42 is alternatively configured or where thesupport body 18 is devoid of the septum well 42 (e.g., where theinjection site 12 does not include the septum unit 20). It is alsopossible for the inventive aspects of the valve component to be usedwithout the septum unit 20.

The mid-section 44 is integrally formed with and extends distally fromthe septum well 42 and presents an axially-extending proximal passageway54. The passageway 54 extends through the central apex 53 of theseptum-engaging surface 50. The preferred passageway 54 has a diameterthat ranges from about 0.099 inches to about 0.112 inches. Themid-section 44 serves as the fluid connection between the septum well 42and the cup-like structure that holds the flow control valve 24, andthereby provides a space for receiving the distal end of cannula 16during cannula insertion (see FIG. 5). However, it is also within thescope of the present invention to have additional or alternativestructure provided to interconnect the cup-like structure and septumwell 42. Furthermore, the support body 18 could be devoid of themid-section 44 so that the septum well 42 and cup-like structure aredirectly connected.

Turning again to FIGS. 4-7, the cup-like structure is configured to holdthe flow control valve 24, as will be discussed further. The valve seat46 comprises a radially-extending wall attached to the distal end of themid-section 44 and presents a proximal flange-engaging face 56. Thesidewall 48 comprises an annular wall that presents interior, annular,proximal and distal axial surfaces 58,60 that are joined by a shoulder62 (see FIG. 7). The sidewall 48 extends endlessly about the valve seat46 and is preferably integrally formed with the valve seat 46.Preferably, the illustrated surfaces 56,58,60,62 cooperatively form asocket that fluidly communicates with the passageway 54 and isconfigured to receive the flow control valve 24 and luer lock fitting22. However, for some aspects of the present invention, the preferredsocket could be alternatively configured to receive the luer lockfitting 22 and flow control valve 24. The sidewall 48 presents anoutermost diameter of the injection site that is preferably less thanabout one (1) inch and, more preferably, is less than about 9/16 of aninch.

The split septum unit 20 preferably includes a resilient elastomericseptum body 64, and an annular rigid synthetic resin septum holder 66.However, the principles of the present invention are applicable wherethe septum unit 20 does not include the holder 66. The illustratedholder 66 has opposed, annular, proximal and distal ends 68,70, and isdisposed about body 64. The outer surface of the holder 66 also has anoutwardly projecting, annular detent 72. As illustrated, the outerperiphery of resilient body 64 has an annular groove 74, while the innersurface of holder 66 is equipped with a mating, annular rib 76; theinterfit of rib 76 into groove 74 securely fastens the holder 66 to body64. The internal diameter of the ring-shaped septum holder 66 and theouter diameter of the septum body 64 are preferably dimensioned toclosely complement one another, whereby the septum holder 66 provideslittle or no pre-loading of the septum body 64.

The body 64 also presents a split 78 extending fore and aft betweenproximal and distal faces 80,82 thereof. This allows insertion ofcannula 16 through the septum unit 20, as will be described. The split78 is preferably a tri-slit (or Y-shaped slit), although a linear splitor other split configurations are entirely within the ambit of thepresent invention. However, those ordinarily skilled in the art willappreciate that certain principles of the present invention are notlimited to the illustrated septum design. For example, the septum holder66 is not always required or the design of the septum body 64 may bevaried, such as changing the configuration of the split. Furthermore,for some aspects of the present invention, the injection site could bedevoid of the septum unit 20 entirely (e.g., the site 12 mayalternatively include a luer lock connection in place of the splitseptum).

In the illustrated embodiment, the holder 66 projects proximally fromthe well 42 so that the proximal terminal face 68 of the holder 66 isspaced proximally from the proximal terminal face 80 of the support body18. Moreover, the body 64 and holder 66 are preferably configured topresent a substantially coplanar proximal septum surface (cooperativelydefined by faces 68 and 80). This arrangement provides a generallysmooth swabable surface that greatly enhances the cleanliness of thesite 12. However, it is entirely within the ambit of certain aspects ofthe present invention to provide the site 12 with an alternativeproximal configuration. For example, the proximal surfaces of septumbody 64, septum holder 66, and well 42 may be axially offset relative toone another. Furthermore, if desired, the proximal face of the well 42could also be coplanar with the faces 68 and 80. In the preferredembodiment, the faces 68 and 80 are not coplanar until the unit 20 isreceived within the well 42, whereupon the septum body 64 is preloadedand deflected proximally into flush relationship with the proximal face68 (see FIGS. 4 and 7).

The septum unit 20 is received within well 46, with the septum body 64preferably being preloaded as previously described. Furthermore, theunit 20 is inserted into well 42 until the detent 72 is seated withingroove 52, which provides further pre-compression (or at leastresistance to radial deflection) of the septum body 64. Yet further, asthe septum unit 20 is seated within the well 42, the outer periphery ofdistal face 82 of body 64 comes into firm contact with the protrudingseptum-engaging surface 50. Consequently, the body 64 is compressed byand assumes a shape complemental to the surface 50 (see FIGS. 4-7).Additional details and advantages concerning the preferred septum unit24 and the interconnection between the septum well 42 and septum unit 24are disclosed in the above-incorporated U.S. application Ser. No.11/277,471.

Turning to FIGS. 2, 2 a, and 4-7, the luer lock fitting 22 is preferablya unitary fitting molded from a rigid synthetic resin. The fitting 22includes a proximal annular valve seat 84, a distal annular inner barrel86, and a distal, annular, outer, connection wall 88. The fitting 22also presents a proximal connection end 90 with proximal and distalaxial surfaces 92,94, and proximal and distal shoulders 96,98 and isdesigned to be received by the distal socket of the support body 18 (seeFIG. 7). The connection end 90 is designed to mate with the sidewall 48so that respective surfaces 58,92, shoulders 62,96, and surfaces 60,94engage one another to interconnect the fitting 22 and the support body18 and secure the flow control valve 24, as will be discussed further.As best seen in FIG. 7, the annular base 34 of peripheral catheter 14 isthreaded into the fitting 22, between the inner barrel 86 and outerconnection wall 88. The fitting 22 also presents an axially-extendingdistal passageway 100 that extends through the inner barrel 86 and valveseat 84. While the fitting 22 is preferably configured as a luer lockfitting, the principles of the present invention are equally applicablewhere fitting 22 includes a different type of connector for attachmentto the catheter 14 (or for attachment to other infusion/aspiration setcomponents such as a needle or tubing).

The valve seat 84 also presents a distal annular flange-engaging face102 spaced radially between the proximal surface 92 and the passageway100, with the distal face 102 preferably including an endless annulargroove 104 for receiving and holding the flow control valve 24 preciselybetween the support body 18 and fitting 22. However, it is also withinthe scope of the present invention where the valve seat 84 isalternatively configured to receive the flow control valve 24, as willbe discussed further.

Turning to FIGS. 3, 3 a, and 4-7, the flow control valve 24 isconfigured to selectively permit infusion and aspiration fluid flowthrough the injection site 12 and includes a peripheral flange 106 and aconcavo-convex, substantially dome-shaped central body 108 surrounded bythe flange 106. The body 108 and flange 106 are preferably integrallyformed from resilient silicone, but could include another syntheticresin material. The body 108 preferably comprises a wall 110 thatpresents concave and convex surfaces 110 a, 110 b. The wall 110 alsopresents a wall apex and a thickness that decreases progressively to theapex. The body 108 also includes a rib 112 extending along the concavesurface of the wall 110. Yet further, the body 108 presents opposedinterior valve edges 114 that extend perpendicularly relative to the rib112 and extend axially through the body 108 to define a slit 116 (seeFIGS. 4-7). Additional preferred features of the body 108 are disclosedin U.S. patent application Ser. No. 10/304,833, filed Nov. 26, 2002,entitled PRESSURE ACTUATED FLOW CONTROL VALVE, which is herebyincorporated in its entirety by reference herein.

The flange 106 includes an endless annular flange wall 118 surroundingand attached to the body 108 (see FIG. 3 a). The flange 106 alsoincludes an endless annular valve-seating projection 120 extendingdistally from the flange wall 118 and spaced radially between anoutermost edge 122 of the flange wall 118 and the body 108. Preferably,the projection 120 is spaced radially outwardly from the body 108 topermit the edges 114 to flex between open infusion and aspirationconfigurations, as will be discussed. The principles of the presentinvention are also applicable where the projection 120 is alternativelyconfigured to provide a mechanism for precisely seating the flow controlvalve 24 within the injection site 12. For instance, the projectioncould extend proximally from the flange wall 118. Furthermore, multipleprojections 120 could extend distally and/or proximally from the flangewall 118 to secure the flow control valve 24. For example, theprojection 120 could comprise multiple arcuate segments that are spacedcircumferentially from one another and cooperatively extend about thebody 108. Alternatively, the projection 120 could include multipleradially-spaced segments.

The flow control valve 24 is assembled between the support body 18 andfitting 22 by positioning the valve 24 on valve seat 84. In particular,the apex of the valve 24 is inserted into a proximal end of thepassageway 100, and the projection 120 is inserted into the annulargroove 104. The projection 120 and groove 104 are preferably shaped toguide the flow control valve 24 into axial alignment with the fitting22. Preferably, the groove 104 and projection 120 are complementallyshaped so that the projection 120 fits snugly within the groove 104 andthe flow control valve 24 is coaxially aligned with the fitting 22(thereby positioning the dome-shaped central body 108 concentricallywithin the passageway 100). In this manner, the interengagement betweenthe groove 104 and projection 120 restricts relative radial movementbetween the flow control valve 24, support body 18, and fitting 22. Inaddition, the groove 104 and projection 120 permit the flow controlvalve 24 to be selectively angularly rotated about the valve axis andrelative to the support body 18 and fitting 22, although this is likelyunnecessary with the illustrated embodiment because of the symmetricalconstruction of the control valve 24.

The illustrated configuration of groove 104 and projection 120 ispreferred for axially aligning the flow control valve 24 within theinjection site 12. However, it is also within the ambit of the presentinvention where the valve seat 84 presents an alternative opening toreceive the projection 120 and thereby axially (and perhapsrotationally) align the flow control valve 24. For instance, the valveseat 84 could present multiple openings to receive complementalprojecting segments. It is also within the ambit of the presentinvention where the projection 120 extends proximally from flange wall118 and is received by a groove in valve seat 46. Furthermore, bothvalve seats 46,84 could include grooves for receiving complementaloppositely extending projections of the flow control valve 24.

The flow control valve 24 is also positioned onto the valve seat 46 bylocating a proximal surface of the flange wall 118 against theflange-engaging face 56. As discussed previously, the fitting 22 issecured to the support body 18 by inserting the connection end 90 intothe distal socket of the support body 18. The support body 18 andfitting 22 are further secured by attaching respective adjacent pairs ofsurfaces using a conventional ultrasonic welding process to form anhermetic seal between the support body 18 and fitting 22. The principlesof the present invention are also applicable where the support body 18and fitting 22 are alternatively attached to one another, e.g., wherethe support body 18 and fitting 22 are attached by a snap-fitinterengagement or adhered to one another using a suitable adhesive.

With the connection end 90 inserted, the support body 18 and fitting 22cooperatively present an internal valve chamber that receives the flowcontrol valve 24. The faces 56,102 engage the flange wall 118 oncorresponding sides and compress the flange wall 118 into a compressedstate so as to firmly hold the valve 24 within the injection site 12.More preferably, the support body 18 and fitting 22 are interconnectedso that a thickness dimension T (see FIG. 3 a) of the flange wall 118 isaxially compressed from an uncompressed state to the compressed state byan amount that ranges from about 0.003 inches to about 0.008 inches.Most preferably, the amount of compression of the thickness dimension Tbetween uncompressed and compressed states is about 0.005 inches.

The flange wall 118 also presents an outermost diameter D1 thatpreferably ranges from about 0.341 inches to about 0.355 inches. Also,the outermost diameter D1 is preferably less than an outermost chamberdiameter D2 (see FIG. 7). More preferably, the outermost diameter D1ranges from about 0.010 inches to about 0.030 inches smaller than thechamber diameter D2 when the flange wall 118 is in the uncompressedstate. Most preferably, the outermost diameter D1 is about 0.020 inchessmaller than chamber diameter D2. This configuration provides a slightclearance between the flange wall 118 and support body 18. As a result,the illustrated flow control valve 24 can be precisely coaxially alignedwith the support body 18, fitting 22, and passageways 54,100, and theflange wall 116 can be compressed between the support body 18 andfitting 22 while permitting the central body 108 to flex normally toallow aspiration and infusion flow. In particular, it has been foundthat this “loose fit” between the installed flow control valve 24 andaxial surface 58 allows the projection 120 to align the flow controlvalve 24 to the valve seat 84 and restricts inadvertent off-axispositioning of the valve 24 relative to the support body 18 and fitting22. Furthermore, the loose fit between the outermost edge 122 and axialsurface 58 promotes normal opening of the slit 116 for injection andaspiration flow, with inadvertent or premature opening of the slit beingrestricted. Thus, the illustrated injection site 12 is designed tominimize valve failures, particularly those that result from injectionsite manufacturing and assembly.

Turning to FIGS. 4 and 6, the valve 24 is preferably designed toselectively prevent fluid flow in the proximal direction (correspondingto aspiration flow through the injection site 12). More particularly,the valve 24 prevents proximal flow when an aspiration pressuredifferential (i.e., where the pressure against the convex surface 110 bof the wall 110 is greater than the pressure against the concave surface110 a of the wall 110) across the valve 24 is below a set aspirationamount (see FIG. 4). The set aspiration amount is generally greater thanthe venous pressure (relative to atmospheric pressure) of the patientwhen fluid is not being injected or aspirated through the injection site12. That is to say, when the valve 24 experiences the typical venouspressure of the patient, the corresponding aspiration pressuredifferential is less than the set aspiration amount and is notsufficient to open the valve 24 (i.e., the edges 114 are in sealingengagement with each other in the closed configuration). However, whenit is desired to aspirate fluid across the valve 24, fluid can be drawnthrough the injection site 12 by reducing the fluid pressure on aproximal side of the valve 24 (e.g., by drawing fluid with a syringe) sothat the aspiration pressure differential exceeds the set aspirationamount. This causes the valve 24 to open (i.e., as edges 114 shiftproximally and away from each other into the open aspirationconfiguration) and allow aspiration flow through passageways 54,100 (seeFIG. 6).

Turning to FIGS. 4 and 5, the valve 24 is also preferably designed toselectively prevent fluid flow in the distal direction (corresponding toinfusion through the injection site 12) when the valve is in the closedconfiguration. The valve 24 prevents distal flow when an infusionpressure differential (i.e., where the pressure against the concavesurface 110 a of the wall 110 is greater than the pressure against theconvex surface 110 b of the wall 110) across the valve 24 is below a setinfusion amount. When an external pressure is applied to a proximal sideof the valve 24 (e.g., by injecting fluid from a syringe or other fluidsupply) and the infusion pressure differential exceeds the set infusionamount, the valve 24 opens into the open infusion configuration (wherethe edges 114 are shifted distally and away from each other) to allowinfusion flow through passageways 54,100 (see FIG. 5). It is also notedthat the valve 24 is preferably configured so that the set aspirationpressure differential required to open the valve 24 is greater than theset infusion pressure differential required to open the valve 24.

In operation, the injection site 12 permits infusion flow from thecannula 16 to the peripheral catheter 14 when the infusion pressuredifferential exceeds the set infusion amount. During infusion, theinterior valve edges 114 are shifted in the distal direction and atleast partly away from each other to open the slit 116 and allowinfusion flow to pass from the proximal passageway 54 to the distalpassageway 100 (see FIG. 5). Similarly, the injection site 12 permitsaspiration flow from the catheter 14 to the cannula 16 when theaspiration pressure differential exceeds the set aspiration amount.During aspiration, the interior valve edges 114 are shifted in theproximal direction and at least partly away from each other to open theslit 116 and allow aspiration flow to pass from the distal passageway100 to the proximal passageway 54 (see FIG. 6).

The preferred forms of the invention described above are to be used asillustration only, and should not be utilized in a limiting sense ininterpreting the scope of the present invention. Obvious modificationsto the exemplary embodiments, as hereinabove set forth, could be readilymade by those skilled in the art without departing from the spirit ofthe present invention.

The inventors hereby state their intent to rely on the Doctrine ofEquivalents to determine and assess the reasonably fair scope of thepresent invention as pertains to any apparatus not materially departingfrom but outside the literal scope of the invention as set forth in thefollowing claims.

1. An intravascular valve component comprising: a valve case includingattached proximal and distal case portions, said case portionspresenting respective spaced apart fluid ports and a fluid passagewayextending between the ports; and a flexible pressure-actuated flowcontrol valve disposed along the fluid passageway to control fluid flowtherethrough, said valve including a generally dome-shaped central valvewall having a slit at a general apex of the dome and an annular flangesurrounding the central valve wall, said annular flange including aradially-extending flange wall having a radially outermost edge and avalve-seating projection extending axially from the flange wall andspaced radially outwardly from said valve wall and between saidoutermost edge and the valve wall to permit said slit to flex betweenopen infusion and aspiration configurations, one of said case portionspresenting an opening, said opening presenting a generallyarcuate-shaped groove having a tapered inner surface, said projectionbeing generally arcuate-shaped and having a tapered outer surface, saidflange wall being engagingly received between the attached caseportions, wherein said tapered inner surface of the groove and saidtapered outer surface of the projection are complementally shaped suchthat the projection is received within the groove and engages the grooveto substantially restrict radial movement of the flow control valverelative to the valve case and to coaxially align the valve with the oneof said case portions presenting said opening to thereby position thevalve wall concentrically within the fluid passageway.
 2. Theintravascular valve component as claimed in claim 1, said case portionspresenting respective generally planar proximal and distalflange-receiving surfaces opposed to one another, said flange wallpresenting generally planar proximal and distal surfaces respectivelyreceived between said proximal and distal flange-receiving surfaces ofsaid case portions, such that said proximal and distal surfaces of saidflange wall respectively contact a majority of an area of said proximaland distal flange-receiving surfaces to compress the flange wall of theflow control valve therebetween.
 3. The intravascular valve component asclaimed in claim 2, said flange wall comprising an endless annular wallpresenting said radially outermost edge, said case portionscooperatively presenting a valve chamber that receives the annularflange, said valve chamber being partly defined by a radially outermostinternal surface extending axially between the opposed flange-receivingsurfaces and presenting an outermost chamber diameter dimension, saidradially outermost edge having an axially-extending thickness and anuncompressed flange diameter dimension, wherein said uncompressed flangediameter dimension along said edge is less than the outermost chamberdiameter dimension, such that the valve chamber permits radial expansionof the flange wall as the flange wall is compressed between theflange-receiving surfaces, wherein a distance between said radiallyoutermost edge of said uncompressed flange and said radially outermostinternal surface of said valve chamber is substantially the same at amajority of points along said thickness of the outermost edge of theflange.
 4. The intravascular valve component as claimed in claim 3, saiduncompressed flange diameter dimension being about 0.020 inches lessthan the chamber diameter dimension.
 5. The intravascular valvecomponent as claimed in claim 2, said valve wall presenting proximal anddistal valve surfaces, said slit being normally closed and extendingbetween the proximal and distal valve surfaces, said valve wall flexingto open the slit in response to an infusion fluid pressure differentialacross the wall, wherein the pressure against the proximal valve surfaceis greater than the pressure against the distal valve surface, saidvalve wall flexing to open the slit in response to an aspiration fluidpressure differential across the wall, wherein the pressure against thedistal valve surface is greater than the pressure against the proximalvalve surface. 6-8. (canceled)
 9. The intravascular valve component asclaimed in claim 5, said dome-shaped valve wall comprising aconcavo-convex wall that projects distally from the flange wall, withthe proximal valve surface being concave and the distal valve surfacebeing convex.
 10. The intravascular valve component as claimed in claim9, said projection extending distally from the flange wall. 11-15.(canceled)
 16. The intravascular valve component as claimed in claim 9,said projection extending proximally from the flange wall.
 17. Theintravascular valve component as claimed in claim 1, wherein saidprojection engages the groove along said tapered outer surface of theprojection.